By Dr. Robert C. Reiser
Before I was a doctor I was a biologist. From my earliest days I was fascinated by all aspects of Animalia and read voraciously anything I could find on the topic. To this day a prized gift from my youth, the Larousse Encyclopedia of Animal Life, occupies a prominent place on my bookshelf and I still consult it occasionally. So I enjoy the challenge I often face in the ED of identifying various specimens that police and patients bring in.
The police occasionally bring me bones or bone fragments found by some citizen that they want identified as human or not. Sometimes this is straightforward. Adult animal long bones are denser than adult human long bones and are shaped differently. Distinguishing a deer femur from a human femur is easy.
Sometimes it can be more complicated though. Infant bones are very similar in density whether animal or human. Some animals’ body parts resemble humans’ closely. The skeletal appearance of black bear paws for example look very similar to skeletal adult human hands and raccoon paws can be mistaken for children’s hands when all that is left is bones. Bone fragments and small bones are best left to expert forensic anthropologists to try to identify.
More commonly, my patients bring me critters that have bitten them or may have bitten them. From spiders to snakes, caterpillars to bedbugs, ticks, lice, chiggers, centipedes and millipedes, silverfish, cockroaches and various imaginary pests, I sort through it all. I have learned to be wary of the assurances that the critter in the Tupperware is dead; many have recovered by the time I pop off the lid. Generously, I let the residents take the first look now. Some of the specimens have disappeared from their captivity altogether, which can be concerning in its own way. Enjoy the car ride home!
I saw a typical case recently. A young man with a worried expression sat clutching a Tupperware container. He had been bitten on the face by a spider and he was worried that the creature in the container was the dreaded brown recluse spider. Also, he had heard that bites to the face were the most dangerous. I have never heard this.
He had a small area of pale swelling at his temple and two small puncture wounds in the center of the swelling. Yes, a spider bite most likely. Before I could stop him or call a resident over, he had popped the lid of the Tupperware container and thrust it at me for identification. Fortunately what was left of the small brown spider was truly dead and gone. And no, it was not a brown recluse. In fact brown recluse spiders (Loxosceles reclusa) do not even live in Virginia. Their range is in the Midwest.
Brown recluse spiders have an undeserved and outsized reputation for causing human misery. They are shy (hence the reclusa) nocturnal creatures that have small fangs that cannot penetrate most clothing and rarely bite anyway. Most of their bites are when trapped under clothing and result in little more than a small welt. Occasionally though, it is thought (based on limited data), that they can cause a great deal of tissue damage which can take months to heal. There is no antidote and nothing to do.
Brown recluse spiders usually have a violin marking on their cephalothorax, the front portion of their body, but so do other common spiders like the harmless cellar spider, which is found in Virginia. If you really want to identify a brown recluse here is a tip. Unlike most other spiders that have eight eyes brown recluse spiders have six eyes. Good luck trying to count them in a live spider or in a squashed spider though.
My resident finally got around to seeing the young man and examining his spider, which he concluded was a funnel-weaving spider or grass spider. Like all spiders, it is venomous, but it is not really very harmful.
As a biologist I was gratified and impressed that my resident was well enough versed in field biology to be able to tell one spider species from the next and I asked him how he had come to identify it. We do not keep a Larousse encyclopedia in the ED as far as I know. He looked at me with a practiced patience and let me in on a little secret. He and the med student had Googled it.
